use a TODO context

[h8liu]

No description provided.

[peterbourgon]

=== RUN   TestSend
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x7f0865]

goroutine 11 [running]:
net/http.(*Request).WithContext(...)
	/usr/local/go/src/net/http/request.go:353
github.com/aws/aws-sdk-go-v2/aws.setRequestContext(...)
	/home/build/go/src/github.com/aws/aws-sdk-go-v2/aws/request_context.go:11

Doesn't work.

[h8liu]

please take a look.

[h8liu]

not sure why circleci failed this time.

[peterbourgon]

Thank you!